Patriquin in U.S. Pat. No. 4,820,916 discloses an optically powered sensor system. Oota et al. in U.S. Pat. No. 4,601,201 discloses an apparatus for measuring the level of a fluid utilizing a capacitive probe having capacitor plates driven by a high-frequency signal, Col. 2, lines 20-30 and Col. 5, lines 13-31. Kuhnel in U.S. Pat. No. 4,418,569 discloses a capacitive fluid level sensor that utilizes difference amplifiers. Decker in U.S. Pat. No. 4,373,389 relates to capacitive level measurement in which sum and difference values are determined, Col. 1, lines 60-68 and Col. 2, lines 1-5 and 15-22. Gray et al. in U.S. Pat. No. 4,517,547 discloses a water-in-fuel sensor and method, Col. 3, lines 6-60.
In accordance with the present invention, an electronic encoding method is provided for the conversion of a differential capacitive transducer value into timing pulses suitable for transmission over a fiberoptic sensor system network. A reference signal provides for normalization of the sensor value in the event that the total transducer value varies due to environmental influences.